Astigmatic-lens-grinding mechanism.



LI 6. SIMPSON. ASTIGMATIC LENS GRINDING MECHANISM.

APPLICATION FILED AUGJ, I9I6.

Patented Dec. 10, I918.

ITEIR 5 VI E N. i R rm M N m B O 2 a m the abrasive used in g,

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T0 025 wiwm 5e mag; causes" 381$ lincwn citizen me New Yam, haveinvented Grinding Mechanism; and A fcllowing 5:0: be a full, cleai',exact dese *iption 0:? the same, reference being had. in theaccompanying drawings, fez-wing" a pare of this specification, and tothe erect/e .S 0% xeference marked thereon.

My invention relates to grinding me chines and more perticulerlv relatesto a grinding mechanism especial, ly edeptecl 5502 rinding astigmaticlenses, time is, lenses living their two meridians 0f curvature, suchas, cylinder lenses, eerie lenses and prisms.

Salient objects of this invention are: To provide an imprcvecl lensgrinding mechanism of the iype 5511M einbcziies means v cunnecting agrinding shell and lens moms..-

ed on e lens lonely together eriler t0 serve the relaeive angularEQlfii'iS-R ilae time maintain their mericlizmal alinexwent Whereinthose parts which may obstruct 1e sur feces under abrasion, endcrelineciiy we in E lie way of the operate? when he emlezzvur; to applyabrasive material thereto, have bee reduced 9.- minimum;

To provide a lens grinding mechanism a this cliei'ectei, that is s0organized u, may be readily attache. to endmie eclled from crdinaryforms of lens grinii chines in use today;

To "ovicle an improved ceniiecti tween he suppoi'nng d mg meme-- nismand the grimling imple;

T0 provide a imiing in m wherein all. nwving p p2 tectecl mm cling andnclisr the drawings:

Fi we 1 is a right elevei ion gi'in ing machine to which a lens gummechanism constituting an embodiment of my inventicn has been ii plied,she bowl .of the machine having been bfoizen avvay 959 more fullyxiisciose the or; my mventien.

from llie s is jcurnel driven by a mechanism ale such :23 ia jing 211 ngaged by a lens body spindle, and thus when the support .is rotated andthe lens body, which being carried by the grinding shell and driven bythe link in the same general direction as the shell, is held with itsaxis of rotation eccentric to the axis of rotation of the shell or, whatis preferable, when the lens body is moved back and forth across thegrinding shell, which may be done by swinging the lens body spindlelaterally: a differential movement of the grinding shell and the lensbody is produced which sets up a grinding action between the grindingshell and the lens without disturbing the meridianal alinement of thetwo. i

To this end I provide a grinding head 10 which is provided in its underside with a concentric taper socket 11, adapted to fit on the taperedupper end of the grinding spindle 1. On the upper end of the head 10, Iprovide a tapered shank 12 which is designed to receive a grinding shell13, which we will presume is a tor-ie grinding shell having a 6.00diopter curve in one meridian and a 6.75 curve in the other meridian.The shank 12 on the grinding head and the socket 14 of the grindingshell 13 are preterably made the same in size and taper as the grindingspindle 1 and the socket 11. As an additional precaution against thepossibility of relative angular movement between the grinding shell 13and the shank 12, a projecting pin 15 is provided in the shank 12 inposition to engage with the slot 16 which slot is formed as shown, inthe hub of each of the grinding shells that are to be used on the, shank12. By using a single pin 15 and slot .16 each grinding shell willalways set upon the spindle 1 in the same position.

For linking the lens body to the head 10 in such a manner that when alens is blocked thereon and the lens body is arranged in cooperativerelation with a grinding shell mounted on the grinding head, the twogrinding implements, namely the grinding shell and the lens body withits lens, may be maintained in meridianal alinement whether they areactuated or not, that is to say for example, that when the grindingshell rotates for a given angular distance about its axis, the lens bodymust. rotate for exactly the same angular distance in the same generaldirection about its axis; and yet to allow universal tilting movement ofthe lens body or carrier about its connection i I to the grinding head:I provide a rigid lmk connected at one end through a universalconnection to the head 10 and at the other end through a universalcoupling to the lens body.

The universal conncetioi'i at the lower end comprises a. bifurcated yokemember consisting of a shank 20 provided with a pair of yoke arms 21,and in the extremity of each of these arms, is threaded one of a pairofstuds 22, each having an inwardly extending portion upon which ismounted a roller 23. The rollers 23 cooperate with a pair ofdiametrically opposite elongated slots or recesses 24 cut into the sidesof the ball shaped body of the head 10, and extending in the directionof its axis of rotation. This connection permits the shank 20 to beraised or lowered, swung about the axis of the rollers 23, toward andaway from the vertical axis of the head 10 and to be swung laterallyabout an axis intermediate and at right angles to the axis of therollers; but it will not permit of any rotative movement of the shank 20about the vertical axisv of the head 10. The shank 25 of the arm 26,which forms the upper portion of the link connectin the head 10 with thelens body 30, is adjusta 1y secured to the shank 20 of the yoke portionof the link by means of a pair of screws 27 passing through slots 28 inthe shank 25 and threaded into the shank 20 of the yoke member. Tofurther insure the rigidity of the link and to hold the parts inalinement the shank 25 and the shank 20 are joined. together by a tongueand groove connection as best shown in Fig. 2. The screws 27 serve. tohold the two parts of the link rigidly together after the desiredadjustment for length has been made.

The free end of the arm 20 forming the upper portion of the link isenlarged to acconnnodate the removable hardened steel coupling member 31which is preferably threaded therein and is adapted to cooperatesimultaneously with the lower end of the. lens body spindle 2 and withthe lens body 30. forming a universal coupling for guiding and operatingthe lens body and at the same time constraining the motion of the link.

In the upper portion of the coupling member is formed a center 32 in theform of a spherical or conical recess in which the end of the spindlesets and the lower portion of the coupling member is formed into a ballend having a transverse slot out therethrough as best shown in Figs. 1and 2. A socket. preferably a spherical bottomed socket having aremovable pin 36 extending diametrically across its center of curvature,is provided in the lens body 30, and engages with the split ball 33 inthe manner of a clutch or coupling, the end of the ball seating in thebottom of the socket and the pin passing through the slot in the ball.The wall 37 surrounds the socket 35 and extends upwardly for asutiicient height to prevent al 'asive material from accidentallygetting into the bearing, and oil from being thrown out of, the socket.This forms a universal coupling for detachabl y connecting thedrivinglink with the lens body.

i alient features peculiar to the construction at the universal couplingand the adja win-(11y toward a common drip point located Joint to thesecond grinding implement and below said implements and connectingattached at another point to the support means, whereby fluid materialmay collect through universal connecting means, the I at and drip offof, said dri point. portions of the link extending away from LEONSIMPSON. the grinding implements and away from the connecting means eachbeing directed d0wn- Witnesses:

WILLIAM G. Woonwon'rn, GEORGE A. PA E.

